Touching of a capacitive sensor by a human hand or finger, or approaching a capacitive proximity sensor changes certain parameters thereof, in particular the capacitance value of a capacitor that is built into the touch sensor used, for example, in human to machine interface devices, e.g., keypad or keyboard. Microcontrollers now include peripherals that enhance the detection and evaluation of such capacitive touch sensors. One such application utilizes capacitive voltage division (CVD) to evaluate whether a capacitive touch element has been touched or not.
The resolution of capacitive touch systems is limited by the capacitance of the sensor, both the actual sensor and system parasitic capacitances. However, when such sensors are operated in high noise environments with high bulk capacitance, the resolution in conventional systems may not suffice.